Did 928 Specialists stop making X-pipes?
#31
Fleet of Foot
Rennlist Member
Rennlist Member
That's not EGR Andy, just air injection lines to help heat the cats while warming up. If the shop knows anything about the car (doubtful) they will fail your car for tampering regardless of its emissions.
#32
Drifting
If they follow the letter of the law, our cats are not legal anywhere. They are not CARB approved for this specific application.
They do not require an air pump to fire off, that is the only purpose for the air pump. It injects fresh oxygen to make the cats start working earlier after startup. Almost all new cats do not require an air pump. But...if they are looking for it and it's not there or not connected they will probably fail it.
They do not require an air pump to fire off, that is the only purpose for the air pump. It injects fresh oxygen to make the cats start working earlier after startup. Almost all new cats do not require an air pump. But...if they are looking for it and it's not there or not connected they will probably fail it.
#33
Official Bay Area Patriot
Fuse 24 Assassin
Rennlist Member
Fuse 24 Assassin
Rennlist Member
Thread Starter
Sounds like I would have no choice but to use cats that have an air inlet. I would have to figure out how to adapt the inlets to the 928's setup that leads to the smog pump.
#35
Three Wheelin'
I was wondering about that. Putting a bung hole on a cat is no problem, but would it affect the modern cat's performance to have a stream of turbulent air introduced?
Does it matter where you introduce the air? I think if you introduced it late in the catalytic process, all you're doing is diluting the exhaust and possible deceiving the sniffer as to PPM.
Matt
Does it matter where you introduce the air? I think if you introduced it late in the catalytic process, all you're doing is diluting the exhaust and possible deceiving the sniffer as to PPM.
Matt
#36
Fleet of Foot
Rennlist Member
Rennlist Member
If the air system is operating properly the air is diverted away from the cats once in closed loop, hence no dilution. The diverter valve sends the air to the airbox.
#37
Drifting
Bill is correct, the air pump only supplies fresh air to the cats upon startup.
The cats I had made are single stage, you are either before the process or after the process. If you plumbed the air pump into a set of my cats there would probably be no difference either way, emissions or operation.
The cats I had made are single stage, you are either before the process or after the process. If you plumbed the air pump into a set of my cats there would probably be no difference either way, emissions or operation.